In this paper, a two-agent heterogeneous fleet vehicle routing problem with time windows (TAHF_VRPTW) is considered. The objective of the first agent is to minimize the total tardiness and the objective of the second ...
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ISBN:
(纸本)9789819755776;9789819755783
In this paper, a two-agent heterogeneous fleet vehicle routing problem with time windows (TAHF_VRPTW) is considered. The objective of the first agent is to minimize the total tardiness and the objective of the second agent is to minimize the total transportation cost. A new mixed integer programming model (MILP) is built for this problem, and then a new branch and price algorithm (NBAPA) is proposed to address it. In the NBAPA, a genetic algorithm (GA) is developed to construct the initial columns, and a label algorithm is designed to exactly solve sub-problems. If the optimal solution obtained by column generation contains real elements, this solution should be used for branch operation. Extensive computational experiments are conducted on the Solomon benchmark instances. The results show that within the specified time, compared with the standard BAP algorithm (i.e., theBAPwithout usingGAto generate initial columns), theNBAPA can reduce the computation time by an average of 28.32% and the average number of branches by 42.29%.
The shortest path problem exists in variety of areas. A well known shortest path algorithm is Dijkstra's, also called "label algorithm". Experiment results have shown that the "label algorithm"...
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ISBN:
(纸本)9781627485852
The shortest path problem exists in variety of areas. A well known shortest path algorithm is Dijkstra's, also called "label algorithm". Experiment results have shown that the "label algorithm" has the following issues: I.. Its exiting mechanism is effective to undigraph but ineffective to digraph, or even gets into an infinite loop;II. It hasn't addressed the problem of adjacent vertices in shortest path;III.. It hasn't considered the possibility that many vertices may obtain the "p-label" simultaneously. By addressing these issues, we have improved the algorithm significantly. Our experiment results indicate that the three issues have been effectively resolved. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Harbin University of Science and Technology
The shortest path problem exists in variety of areas. A well known shortest path algorithm is Dijkstra's, also called “label algorithm”. Experiment results have shown that the “label algorithm” has the followi...
详细信息
The shortest path problem exists in variety of areas. A well known shortest path algorithm is Dijkstra's, also called “label algorithm”. Experiment results have shown that the “label algorithm” has the following issues: I.. Its exiting mechanism is effective to undigraph but ineffective to digraph, or even gets into an infinite loop; II. It hasn’t addressed the problem of adjacent vertices in shortest path; III.. It hasn’t considered the possibility that many vertices may obtain the “p-label” simultaneously. By addressing these issues, we have improved the algorithm significantly. Our experiment results indicate that the three issues have been effectively resolved.
Irreducible decomposition of monomial ideals has an increasing number of applications from biology to pure math. This paper presents the Slice algorithm for computing irreducible decompositions, Alexander duals and so...
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Irreducible decomposition of monomial ideals has an increasing number of applications from biology to pure math. This paper presents the Slice algorithm for computing irreducible decompositions, Alexander duals and socles of monomial ideals. The paper includes experiments showing good performance in practice. (C) 2008 Elsevier Ltd. All rights reserved.
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